The invention relates to a device for displaying optical information by means of a virtual image, in particular in a motor vehicle. Devices of this type are known from the prior art, wherein the optical information in the form of light beams from an image generating apparatus can be perceived as a virtual image in front of, behind or in a windshield via at least one mirror surface, with the light beams producing a beam path. The image generating apparatus may comprise, for example, an electron tube, a liquid crystal display (LCD) with an associated light source or organic light-emitting diodes (OLED). In order to be able to compensate both for the image geometry and for the eye-correction parameters, such a astigmatism, disparity and coma, an optical system having a plurality of spatially arranged mirrors with freeform surfaces is used in the prior art. The mirror or mirrors must correct the influence of the curvature of the windshield on the image such that the driver can perceive an undistorted image. Furthermore, the mirror or mirrors magnify the image from the image generating apparatus. Since the windshield contours usually have complex, a symmetric surfaces with variable curvatures, and are therefore also referred to as freeform surfaces, the surfaces of the mirror or mirrors also need to be in the form of freeform surfaces. It is disadvantageous in the presently known devices that they require a large installation space which is available only to a limited extent if the device is used as a head-up display in a motor vehicle, since the device is preferably arranged in the cockpit and the cockpit must provide a very large number of functional elements for the motor vehicle, such as conventional instrumentation, installation space for the on-board electronics and space for ventilation ducts.